Search

Infarction of the posterior inferior cerebellar artery (PICA) can lead to ischemic stroke in the lateral medullary oblongata. PICA dissection can also elicit an ischemic event in this region, but its detection on radiological images is difficult because of the small diameter of the vessel. We report a case of Wallenberg syndrome due to PICA dissection in a 48-year-old man, which was difficult to diagnose on first admission. He reported sudden onset of sensory disturbance on the right side of his face, ataxic gait, and headache. Brain magnetic resonance imaging (MRI) revealed a fresh cerebral infarct in the right lateral medulla oblongata. Magnetic resonance angiography (MRA) performed at the time of his admission showed no cerebral vessel abnormalities. An MRI study 18 months after the event revealed a fusiform aneurysm on the lateral medullary segment of the PICA, which was extremely close to the cerebral infarct. We concluded that the infarct was due to PICA dissection because of the sudden onset of symptoms and because the infarcted territory of the occluded penetrating branch of the dissecting aneurysm was consistent with Wallenberg syndrome. The aneurysm was trapped and an occipital artery-PICA bypass was placed. At the latest follow-up, 1 year after the procedure, he had no neurological symptoms. Imaging findings at the time of his first admission indicated that the PICA was intact. However, 18 months later, MRI revealed enlargement of an aneurysm at the site of the dissection. A cerebral infarct with headache may indicate PICA dissection.

Middle cerebral artery (MCA) dissection is rare, and various clinical presentations, including hemorrhage, ischemia, or comorbidities, and the changes in imaging findings over time hinder treatment decisions. The European Stroke Organization guidelines exclude MCA dissection. Few cases have been reported with no review of the relevant literature. Therefore, we reviewed the relevant literature and our own experience with non-traumatic MCA dissection cases to determine appropriate treatment strategies. At our institution and affiliated institutions, we encountered six cases of MCA dissection-five with infarction and one with hemorrhage. Two patients underwent revascularization, and one underwent an aneurysmectomy. We reviewed English and Japanese articles in PubMed and Medical Journal Web and summarized the results based on the relationships among age, sex, location, the presence of an aneurysm, the presence of angiography, history, treatment, and mode of onset. The clinical course, changes in imaging, treatment strategies, and prognosis were discussed. Eighty cases were included in the review. Cerebral aneurysms were more common distal to the M2 area (p = 0.00) and were correlated with hemorrhage (p < 0.001). Most hemorrhagic cases with aneurysms were treated surgically, while ischemic cases were treated with antithrombotic agents, and both had a similar neurological prognosis. There were some cases of rebleeding after antithrombotic therapy, especially in older adults.Surgical treatment is recommended in cases of hemorrhage and confirmed aneurysms, particularly for lesions distal to the M2 area. Patients with aneurysm-associated ischemia should be followed up, and antithrombotic treatment should be considered with particular care in older adults., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Internal carotid artery (ICA) ligation for placing a high-flow extracranial-intracranial (EC-IC) bypass is used in patients with aneurysms on the cavernous portion of the ICA. Recanalization and rupture after proximal ICA ligation can occur. We present four patients who underwent endovascular distal ICA occlusion and report our surgical technique and treatment results. We ligated the ICA to place an EC-IC bypass using a radial artery (RA) graft. Failure to obtain spontaneous occlusion in the distal region required endovascular treatment an average of 219 days later. A guide catheter was placed in the common carotid artery, a guide or distal access catheter was introduced in the RA graft from the external carotid artery, and a microcatheter was navigated into the cavernous aneurysm through the RA graft. Using detachable coils, endovascular ICA occlusion was from just distal to the aneurysmal neck to a site proximal to the origin of the ophthalmic artery. Aneurysmal occlusion was completed by endovascular occlusion of the distal ICA. Complications were RA graft stenosis and transient consciousness disturbance due to local subarachnoid hemorrhage. Outpatient follow-up for a mean of 109.5 months revealed no recurrences. Distal occlusion of the ICA through the implanted RA graft is simple and presents a low risk for cerebral infarction due to thrombus formation during the procedure. To treat cavernous carotid aneurysms that do not disappear after placing the EC-IC bypass after ICA ligation at the aneurysmal neck, we offer our procedure as a treatment option.

Background: Large basilar trunk aneurysm caused by bilateral occlusion of the proximal common carotid artery is rare. We treated one case with vertebral V3 portion-radial artery-distal common carotid artery (V3-RA-dCCA) bypass., Case Description: Basilar trunk aneurysm and bilateral occlusion of the proximal CCA were found incidentally in a 70-year-old woman. During the next 5 years, the aneurysm gradually enlarged to 12 mm, and blood flow of the anterior circulation was supplied through the posterior communicating artery. V3-RA-dCCA bypass was performed to reduce the stress of blood flow and prevent aneurysm growth and rupture. After exposing the neck portion, forearm of RA, and V3 portion of the vertebral artery, we created a space just below the sternocleidomastoid muscle to bypass the RA. We flushed the RA with albumin to stiffen the artery and temporarily clamped the bilateral sides of the RA to prevent twisting. We anastomosed the V3 and RA with a 9-0 thread and temporarily clamped the V3. After flushing the RA with albumin to prevent twisting, we clamped the external and internal carotid arteries, opened the dCCA with a vascular punch to prevent arterial dissection, and anastomosed the RA to the dCCA. The patency of the bypass was confirmed with Doppler and indocyanine green video angiography. The postoperative course was uneventful, bypass patency was good, and the aneurysm did not expand further., Conclusion: V3-RA-dCCA bypass may be an effective and low-risk treatment for large basilar trunk aneurysms with bilateral occlusion of the proximal common carotid artery., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Background and Purpose: In previous studies, women had a higher risk of rupture of intracranial aneurysms than men, but female sex was not an independent risk factor. This may be explained by a higher prevalence of patient- or aneurysm-related risk factors for rupture in women than in men or by insufficient power of previous studies. We assessed sex differences in rupture rate taking into account other patient- and aneurysm-related risk factors for aneurysmal rupture., Methods: We searched Embase and Pubmed for articles published until December 1, 2020. Cohorts with available individual patient data were included in our meta-analysis. We compared rupture rates of women versus men using a Cox proportional hazard regression model adjusted for the PHASES score (Population, Hypertension, Age, Size of Aneurysm, Earlier Subarachnoid Hemorrhage From Another Aneurysm, Site of Aneurysm), smoking, and a positive family history of aneurysmal subarachnoid hemorrhage., Results: We pooled individual patient data from 9 cohorts totaling 9940 patients (6555 women, 66%) with 12 193 unruptured intracranial aneurysms, and 24 357 person-years follow-up. Rupture occurred in 163 women (rupture rate 1.04%/person-years [95% CI, 0.89-1.21]) and 63 men (rupture rate 0.74%/person-years [95% CI, 0.58-0.94]). Women were older (61.9 versus 59.5 years), were less often smokers (20% versus 44%), more often had internal carotid artery aneurysms (24% versus 17%), and larger sized aneurysms (≥7 mm, 24% versus 23%) than men. The unadjusted women-to-men hazard ratio was 1.43 (95% CI, 1.07-1.93) and the adjusted women/men ratio was 1.39 (95% CI, 1.02-1.90)., Conclusions: Women have a higher risk of aneurysmal rupture than men and this sex difference is not explained by differences in patient- and aneurysm-related risk factors for aneurysmal rupture. Future studies should focus on the factors explaining the higher risk of aneurysmal rupture in women.

Each year, the Japan Neurosurgical Society (JNS) reports up-to-date statistics from the Japan Neurosurgical Database regarding case volume, patient demographics, and in-hospital outcomes of the overall cohort and neurosurgical subgroup according to the major classifications of main diagnosis. We hereby report patient demographics, in-hospital mortality, length of hospital stay, purpose of admission, number of medical management, direct surgery, endovascular treatment, and radiosurgery of the patients based on the major classifications and/or main diagnosis registered in 2018 and 2019 in the overall cohort (523283 and 571143 patients, respectively) and neurosurgical subgroup (177184 and 191595 patients, respectively). The patient demographics, disease severity, proportion of purpose of admission (e.g., operation, 33.9-33.5%) and emergent admission (68.4-67.8%), and in-hospital mortality (e.g., cerebrovascular diseases, 6.3-6.5%; brain tumor, 3.1-3%; and neurotrauma, 4.3%) in the overall cohort were comparable between 2018 and 2019. In total, 207783 and 225217 neurosurgical procedures were performed in the neurosurgical subgroup in 2018 and 2019, respectively, of which endovascular treatment comprised 19.1% and 20.3%, respectively. Neurosurgical management of chronic subdural hematoma (19.4-18.9%) and cerebral aneurysm (15.4-14.8%) was most common. Notably, the proportion of management of ischemic stroke/transient ischemic attack, including recombinant tissue plasminogen activator infusion and endovascular acute reperfusion therapy, increased from 7.5% in 2018 to 8.8% in 2019. The JNS statistical update represents a critical resource for the lay public, policy makers, media professionals, neurosurgeons, healthcare administrators, researchers, health advocates, and others seeking the best available data on neurosurgical practice.

Background and Objectives: We combined individual patient data (IPD) from prospective cohorts of patients with unruptured intracranial aneurysms (UIAs) to assess to what extent patients with familial UIA have a higher rupture risk than those with sporadic UIA., Methods: For this IPD meta-analysis, we performed an Embase and PubMed search for studies published up to December 1, 2020. We included studies that (1) had a prospective study design; (2) included 50 or more patients with UIA; (3) studied the natural course of UIA and risk factors for aneurysm rupture including family history for aneurysmal subarachnoid haemorrhage and UIA; and (4) had aneurysm rupture as an outcome. Cohorts with available IPD were included. All studies included patients with newly diagnosed UIA visiting one of the study centers. The primary outcome was aneurysmal rupture. Patients with polycystic kidney disease and moyamoya disease were excluded. We compared rupture rates of familial vs sporadic UIA using a Cox proportional hazard regression model adjusted for PHASES score and smoking. We performed 2 analyses: (1) only studies defining first-degree relatives as parents, children, and siblings and (2) all studies, including those in which first-degree relatives are defined as only parents and children, but not siblings., Results: We pooled IPD from 8 cohorts with a low and moderate risk of bias. First-degree relatives were defined as parents, siblings, and children in 6 cohorts (29% Dutch, 55% Finnish, 15% Japanese), totaling 2,297 patients (17% familial, 399 patients) with 3,089 UIAs and 7,301 person-years follow-up. Rupture occurred in 10 familial cases (rupture rate: 0.89%/person-year; 95% confidence interval [CI] 0.45-1.59) and 41 sporadic cases (0.66%/person-year; 95% CI 0.48-0.89); adjusted hazard ratio (HR) for familial cases 2.56 (95% CI 1.18-5.56). After adding the 2 cohorts excluding siblings as first-degree relatives, resulting in 9,511 patients, the adjusted HR was 1.44 (95% CI 0.86-2.40)., Discussion: The risk of rupture of UIA is 2.5 times higher, with a range from a 1.2 to 5 times higher risk, in familial than in sporadic UIA. When assessing the risk of rupture in UIA, family history should be taken into account., (© 2021 American Academy of Neurology.)

Importance: Unruptured intracranial aneurysms not undergoing preventive endovascular or neurosurgical treatment are often monitored radiologically to detect aneurysm growth, which is associated with an increase in risk of rupture. However, the absolute risk of aneurysm rupture after detection of growth remains unclear., Objective: To determine the absolute risk of rupture of an aneurysm after detection of growth during follow-up and to develop a prediction model for rupture., Design, Setting, and Participants: Individual patient data were obtained from 15 international cohorts. Patients 18 years and older who had follow-up imaging for at least 1 untreated unruptured intracranial aneurysm with growth detected at follow-up imaging and with 1 day or longer of follow-up after growth were included. Fusiform or arteriovenous malformation-related aneurysms were excluded. Of the 5166 eligible patients who had follow-up imaging for intracranial aneurysms, 4827 were excluded because no aneurysm growth was detected, and 27 were excluded because they had less than 1 day follow-up after detection of growth., Exposures: All included aneurysms had growth, defined as 1 mm or greater increase in 1 direction at follow-up imaging., Main Outcomes and Measures: The primary outcome was aneurysm rupture. The absolute risk of rupture was measured with the Kaplan-Meier estimate at 3 time points (6 months, 1 year, and 2 years) after initial growth. Cox proportional hazards regression was used to identify predictors of rupture after growth detection., Results: A total of 312 patients were included (223 [71%] were women; mean [SD] age, 61 [12] years) with 329 aneurysms with growth. During 864 aneurysm-years of follow-up, 25 (7.6%) of these aneurysms ruptured. The absolute risk of rupture after growth was 2.9% (95% CI, 0.9-4.9) at 6 months, 4.3% (95% CI, 1.9-6.7) at 1 year, and 6.0% (95% CI, 2.9-9.1) at 2 years. In multivariable analyses, predictors of rupture were size (7 mm or larger hazard ratio, 3.1; 95% CI, 1.4-7.2), shape (irregular hazard ratio, 2.9; 95% CI, 1.3-6.5), and site (middle cerebral artery hazard ratio, 3.6; 95% CI, 0.8-16.3; anterior cerebral artery, posterior communicating artery, or posterior circulation hazard ratio, 2.8; 95% CI, 0.6-13.0). In the triple-S (size, site, shape) prediction model, the 1-year risk of rupture ranged from 2.1% to 10.6%., Conclusion and Relevance: Within 1 year after growth detection, rupture occurred in approximately 1 of 25 aneurysms. The triple-S risk prediction model can be used to estimate absolute risk of rupture for the initial period after detection of growth.

A mutation in RNF213 (c.14576G>A), a gene associated with moyamoya disease (>80%), plays a role in terminal internal carotid artery (ICA) stenosis (>15%) (ICS). Studies on RNF213 and cerebral aneurysms (AN), which did not focus on the site of origin or morphology, could not elucidate the relationship between the two. However, a report suggested a relationship between RNF213 and AN in French-Canadians. Here, we investigated the relationship between ICA saccular aneurysm (ICA-AN) and RNF213 . We analyzed RNF213 expression in subjects with ICA-AN and atherosclerotic ICS. Cases with a family history of moyamoya disease were excluded. AN smaller than 4 mm were confirmed as AN only by surgical or angiographic findings. RNF213 was detected in 12.2% of patients with ICA-AN and 13.6% of patients with ICS; patients with ICA-AN and ICS had a similar risk of RNF213 mutation expression (odds ratio, 0.884; 95% confidence interval, 0.199-3.91; p = 0.871). The relationship between ICA-AN and RNF213 (c.14576G>A) was not correlated with the location of the ICA and bifurcation, presence of rupture, or multiplicity. When the etiology and location of AN were more restricted, the incidence of RNF213 mutations in ICA-AN was higher than that reported in previous studies. Our results suggest that strict maternal vessel selection and pathological selection of AN morphology may reveal an association between genetic mutations and ICA-AN development. The results of this study may form a basis for further research on systemic vascular diseases, in which the RNF213 (c.14576G>A) mutation has been implicated.

Objective: To examine the relationship between trap location and cerebral infarction in the anterior choroidal artery (AChA) region and associated risks in ruptured internal carotid artery blood blister-like aneurysm (BLA) treatment with high-flow bypass and lesion trapping., Methods: We included 26 patients diagnosed with BLAs and treated with high-flow bypass and trapping. We examined clinical characteristics including age, aneurysm trap location, final prognosis, cerebral infarction on postoperative magnetic resonance imaging, and modified Rankin Scale score at discharge. We also searched the literature for similar studies., Results: The modified Rankin Scale score at discharge was 0-2 in 20 patients, 3-5 in 2 patients, and 6 in 2 patients. In 19/26 patients (73.1%), the trapped segment was between the posterior communicating (PcomA) and the ophthalmic arteries. In 2 patients (7.7%), the trapped segment included the PcomA and the AChA; in 4 patients (15.4%), the trapped segment was within the PcomA. In these patients, the PcomA was occluded, and blood from the high-flow bypass flowed out to the AChA alone. No patient showed cerebral infarction. Our systematic review identified 70 patients. Of all 96 patients, 12 had AChA cerebral infarction; however, the infarction affected the prognosis of only 2 patients., Conclusions: When treating BLAs with high-flow bypass and lesion trapping, the frequency of AChA cerebral infarction is low even when the PcomA is occluded, leaving the AChA as the only outflow vessel during high-flow bypass. However, PcomA occlusion may be associated with risks when treating patients with advanced arteriosclerosis near C1-2., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Unruptured intracranial aneurysms are rare and occur in approximately 3% of adults. Explaining the natural course of aneurysms and risk communication are challenging because most patients are asymptomatic and patients' perceived risk often exceeds the actual risk. This article discusses the following five aspects of risk communication on the natural course of the disease and treatment decisions: 1) the natural course of cerebral aneurysms, 2) how aneurysms should be followed upon if no interventions are planned, 3) how to explain treatment risks, 4) whether follow-ups are needed after treatment, and 5) lifestyle-related behaviors to prevent rupture. Discussions with patients should be carefully planned to avoid increased stress and fear. Long-term follow-up data of patients who did not undergo interventions indicated that only 25% of patients with aneurysms experienced a fatal rupture; most die from other causes. Patients with aneurysms require education on lifestyle-related risk factors such as hypertension, smoking, and lack of daily exercise.

Background: Giant fusiform and dolichoectatic aneurysms of the basilar trunk and vertebrobasilar junction (BTVBJ-GFDA) are extremely difficult to treat., Objective: To evaluate factors influencing survival and outcome of BTVBJ-GFDA by performing a retrospective multicenter cohort study., Methods: A total of 32 patients with BTVBJ-GFDA were included in this study. Clinicopathological characteristics, treatment measures, and outcomes were collected from medical records and imaging studies. Autopsy and histological findings of the aneurysm and adjacent brain tissue were also obtained in 9 cases., Results: A total of 11 patients did not undergo surgery, of whom 10 died; 3 from progressive brainstem compression, 4 from subarachnoid hemorrhage, 2 from brainstem infarction, and 1 from associated atherosclerotic disease. The remaining 21 patients underwent a surgical treatment, consisting of immediately proximal parent artery occlusion, remotely proximal parent artery occlusion, clip reconstruction, and distal bypass and achieved significantly longer overall survival compared with those who received conservative therapy (adjusted hazard ratio 1.508, 95% CI 1.058-2.148, P = .02). Histological examination of the aneurysms demonstrated staged clots, open lumen, and intrathrombotic channels with endothelial lining. The patients younger than 45 yr of age showed statistically longer survival than those equal and older than 45 yr (P = .03)., Conclusion: Surgical intervention achieved greater survival than conservative management in BTVBJ-GFDA. Narrow ideal treatment window of the blood flow within the aneurysm to maintain sufficient but not excess supply should be targeted based on the hemodynamics of both the posterior communicating arteries and perforating vessel collaterals., (© Congress of Neurological Surgeons 2020.)

Introduction: We aimed to identify the risk factors for surgical treatment of unruptured intracranial aneurysms (UIAs) in individuals aged >60 years, particularly focusing on white matter lesions (WMLs)., Material and Methods: We investigated a total of 214 patients with UIAs. The patient group comprised 53 males and 151 females with an average age of 68.2 years. UIA size ranged from 2.7 to 26 (mean: 7.3) mm. The primary endpoint of the study was patient prognosis evaluated at the time of discharge using the modified Rankin Scale. We examined the risk factors for poor outcome and WMLs using magnetic resonance imaging., Results: Poor outcome was observed in 23 (10.7%) patients. Significant correlations were observed between poor outcome and UIA size (P < 0.0001), UIAs located posteriorly (P = 0.0204), UIA thrombosis (P = 0.0002), and presence of WMLs (P < 0.0001) in univariate regression analysis. However, no significant correlations were noted between poor outcome and age (P = 0.1438). Multivariate logistic regression analyses showed significant correlations between poor outcome and UIA size (P < 0.0001), presence of WMLs (P = 0.001). Severe WMLs based on the Fazekas classification was correlated to age (P < 0.0001) and atherosclerosis (P = 0.0001). Severe WMLs were associated with ischemia (P < 0.001) and epilepsy (P = 0.0502) as well as length of hospitalization (P < 0.0001)., Conclusion: Severe WMLs are risk factors for surgical treatment of UIAs in the elderly. Surgical indications must be considered and caution should be taken when managing patients with severe WMLs., Competing Interests: Declaration of Competing Interest None of authors have any conflicts of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: There have been reports on postoperative ischemic complications with vascular reconstructive surgery. However, various factors, such as lesions, operative technique, and perioperative treatment, prevent analyzing the causes of ischemic complications in vascular reconstruction surgeries. In the present study, we analyzed the cause of ischemic complications for vascular reconstruction surgeries with the same operator, surgical procedure, and perioperative treatment and without focusing on the lesions., Patients and Methods: We retrospectively reviewed 66 patients, including 24 aneurysm cases and 42 ischemic disease cases, between 2008 and 2018. The patient group comprised 35 males and 31 females, and the patient mean age was 63.3 (23-87) years. We investigated the postoperative presence of symptomatic and asymptomatic cerebral ischemia on MRIDWI performed within 4 postoperative days. We conducted a statistical analysis of the ischemic complications and clinical and treatment factors., Results: Symptomatic cerebral ischemia was detected in 3 cases, whereas asymptomatic ischemic findings were identified in 8 cases. All cases of symptomatic cerebral ischemia involved cerebral aneurysms. Results of a univariate analysis revealed an association between symptomatic cerebral ischemia and preoperative antithrombotic therapy (OR, 0.07; p =  0.049 (95 %CI; 0.007-0.8794)), clipping (OR, 4.8; p =  0.0501 (95 %CI; 1.641-342.9)), and aneurysm (OR, 14.16; p =  0.0423 (95 %CI; 0.6991-286.9)). Significant associations were found between asymptomatic cerebral ischemia and preoperative antithrombotic therapy [OR, 0.2941; p =  0.0514 (95 %CI; 0.08335-1.038)], aneurysms [OR, 7.8; p =  0.0146 (95 %CI; 1.414-43.04)] and radial artery grafts (RAGs) [OR, 6.8; p =  0.0192 (95 %CI; 1.410-32.98)]. Multivariate analysis identified clipping [OR, 5.462; p =  0.045 (95 %CI; 1.01-78.25] and preoperative antithrombotic therapy [OR, 0.187; p =  0.037 (95 %CI; 0.004-0.813)] as the risk factors for symptomatic cerebral ischemia. Further, a correlation was found between asymptomatic cerebral ischemia and RAGs [OR, 9.244; p =  0.00013 (95 %CI; 2.34-29.44)]., Conclusion: Ischemic complications associated with combined vascular reconstruction surgeries for cerebral aneurysms are possibly associated with procedures related to aneurysmal occlusions. Thus, vascular reconstruction surgeries can be performed relatively safely. Further, preoperative antithrombotic treatment should be considered, and caution is required for asymptomatic cerebral ischemia in RAG cases., Competing Interests: Declaration of Competing Interest None of the authors have any conflicts of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: This study aimed to compare the functional outcome at discharge for unruptured cerebral aneurysms (UCAs) between surgical clipping and endovascular coiling in total, nonelderly (<65 years), and elderly (≥65 years) patients by nonbiased analysis based on a national database in Japan., Methods: A total of 15,671 patients with UCA were registered in the Diagnosis Procedure Combination, the nationwide database, from 2010 to 2015 in Japan. The outcome of the Barthel Index (BI) at discharge was investigated, and propensity score-matched analysis was conducted in total, nonelderly, and elderly patient groups., Results: Propensity score-matched analysis found no significant difference for in-hospital mortality between the 2 treatment methods in the total and both age-groups. The rate of morbidity of BI <90 at discharge was higher after surgical clipping than after endovascular coiling in the total (4.9% vs. 3.9%; P = 0.040; risk difference, -1.0%; 95% confidence interval, -3.6 to 2.3%) and the elderly age-group (8.1% vs. 5.0%; P < 0.001; risk difference, -3.1%; -4.8% to 1.5%), however, no significant association between the 2 treatment methods (2.4% vs. 2.6%; P = 0.67; risk difference, 0.22%; -0.79 to 1.22%) was found in the nonelderly group., Conclusions: In elderly patients with UCA, a better outcome at discharge after endovascular coiling was found. However, no significantly different functional outcome at discharge between surgical clipping and endovascular coiling for UCA in nonelderly patients was confirmed by propensity score-matched analysis from a nationwide database in Japan., (Copyright © 2020 Elsevier Inc. All rights reserved.)

There has never been evidence for aneurysmal subarachnoid hemorrhage (aSAH) by endovascular coiling compared to surgical clipping with all grade. The present study and meta-analysis aimed to clarify the in-hospital mortality and poor outcome in the nationwide databases of patients with all grade aSAH between them. The outcome of modified Rankin scale (mRS) at discharge was investigated according to the comprehensive nationwide database in Japan. The propensity score-matched analysis was conducted among patients with aSAH in this database registered between 2010 and 2015. Meta-analysis of studies was conducted based on the nationwide databases published from 2007 to 2018. According to this propensity score-matched analysis, no significant association for poor outcome of mRS > 2 was shown between surgical clipping and endovascular coiling (47.7% vs 48.3%, p = 0.48). However, significantly lower in-hospital mortality was revealed after surgical clipping than endovascular coiling (7.1% vs 12.2%, p < 0.001). Meta-analysis of propensity score-matched analysis in the nationwide database showed no significant association for poor outcome at discharge between them (odds ratio [OR], 1.08; 95% confidence interval [CI], 0.93 to 1.26; p = 0.31). Meta-analysis of propensity score-matched analysis for in-hospital mortality was lower after surgical clipping than after endovascular coiling, however, without significant difference (OR, 0.74; 95% CI, 0.52 to 1.04; p = 0.08). Further prospective randomized controlled study with all grade aSAH should be necessary to validate the in-hospital mortality and poor outcome.

Objective: There has been no precise guide for treatment management of aneurysmal subarachnoid hemorrhage (aSAH) based on the patient's age and treatment method. This study clarifies each risk management for aSAH according to age and treatment method listed in a nationwide database., Methods: We compared 2 groups of patients (nonelderly, <65 years; elderly, ≥65 years) who underwent surgical clipping or endovascular coiling and were registered in a nationwide database in Japan from 2010 to 2015. The odds ratio (OR) and 95% confidence interval (CI) of each risk factor were calculated through multivariate logistic regression analysis for poor outcome according to a modified Rankin Scale score >2 at discharge for each group., Results: In all groups, the risk factors for poor outcome were older age, male sex, neurologic grade on admission, diabetes mellitus, and use of anticoagulation drugs. Inverse risk factors were a high-volume hospital, academic hospital, hypertension, and use of an antiplatelet drug (OR, 0.63-0.81; 95% CI, 0.56-0.88). Chronic heart disease was also a risk factor, but use of a statin drug (OR, 0.85-0.87; 95% CI, 0.76-0.97) and location other than on the anterior communicating artery (OR, 0.74-0.80; 95% CI, 0.67-0.91) were inverse risks in both the elderly and the endovascular coiling groups., Conclusions: Management for patients with aneurysmal subarachnoid hemorrhage was recommended in high-volume and academic institutes with the administration of antiplatelet drugs and consideration of several risk factors. Elderly patients undergoing endovascular coiling might be better given a statin drug, and patients with chronic heart failure or an anterior communicating artery aneurysm should be treated more carefully., (Copyright © 2019. Published by Elsevier Inc.)

Background: This study aimed to clarify the risk factors of treatment for unruptured cerebral aneurysms (UCAs) in elderly patients by comparing the morbidity at discharge between surgical clipping and endovascular coiling in nonelderly (<65 years) and elderly (≥65 years) patients based on a national database in Japan., Methods: A total of 36,017, including 15,671 patients with UCA after exclusion of unknown location, were registered in the Diagnosis Procedure Combination, the nationwide database, from 2010 to 2015 in Japan. Outcome of Barthel Index at discharge was investigated and multivariate logistic regression analysis identified risk factors for morbidity of Barthel Index <90 at discharge in nonelderly and elderly patient groups., Results: Risk factors for morbidity at discharge were basilar artery aneurysm compared with internal carotid artery (ICA), diabetes mellitus (odds ratio [OR], 2.0-2.5; 95% confidence interval [CI], 1.6-3.7), antiplatelet drug, and anticoagulation drug; however, highest hospital volume compared with lowest was an inverse risk factor in both age groups. Endovascular coiling (OR, 0.4; 95% CI, 0.3-0.5) was a significantly inverse risk in the elderly group. Anterior communicating artery aneurysm compared with ICA was a significant risk (OR, 1.6; 95% CI, 1.0-2.6) in the nonelderly group; on the other hand, anterior communicating artery aneurysm (OR, 0.7; 95% CI, 0.5-0.95) and middle cerebral artery aneurysm (OR, 0.6; 95% CI, 0.5-0.8) compared with ICA were significantly inverse risks in the elderly group., Conclusions: Endovascular coiling after control of diabetes mellitus was recommended for the treatment of UCA in elderly patients. The ICA location of aneurysm in the elderly should be paid attention as the treatment risk., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The characteristics of cerebral aneurysms in Japan differ from other countries in the higher incidence of unruptured cerebral aneurysm detected by brain check-up screening, higher rupture rate of unruptured cerebral aneurysm, higher incidence of subarachnoid hemorrhage, and superior outcome after subarachnoid hemorrhage based on meta-analysis. Head shape, genetic features, environmental factors, demographics, and medical system in Japan are also different from other countries. Unruptured cerebral aneurysms are 2.8 times more likely to rupture in Japanese than western aneurysms, resulting in the highest incidence of subarachnoid hemorrhage in the world. The exact and specific mechanisms of de novo, growth, and rupture of cerebral aneurysms have not been elucidated. Investigations will contribute to the understanding of cerebral aneurysms and subarachnoid hemorrhage worldwide. Some features of cerebral aneurysm in Japan are discussed for possible research guidance in the elucidation of the predominance of subarachnoid hemorrhage in Japan.

Surgical clipping of an internal carotid artery (ICA)-posterior communicating artery (ICPC) aneurysm is often difficult in cases involving limited space to insert a clip at the proximal aneurysm neck hidden by the tent. In such cases, we perform incision of the anterior petroclinoidal fold to secure the proximal space for clip insertion. Between April 2013 and March 2018, we treated 89 ICPC aneurysm cases by clipping. Incision of the anterior petroclinoidal fold was performed in 15 of the 89 cases (16.8%). Fast imaging employing steady-state acquisition (FIESTA) magnetic resonance imaging (MRI) can indicate the locations of the aneurysm and tent and can help assess the need for tent incision. We widely dissected the distal sylvian fissure and sufficiently exposed around the aneurysmal space. We coagulated and cut the anterior petroclinoidal fold supra between the ICA and proximal neck of the aneurysm using a low-power bipolar system and needles or micro-scissors with care to avoid injury around structures such as the ICA, aneurysm, and oculomotor nerve. When using this strategy, we often select the Yasargil FT717 clip that has a curve along the skull base because of easy insertion. All cases showed complete aneurysm exclusion on three-dimensional computed tomography angiography, and there was no cerebral infarction, neurological deficit (such as hemiparesis), or oculomotor nerve palsy. Therefore, our strategy of incision of the anterior petroclinoidal fold during clipping for securing the proximal space of an ICA aneurysm is effective and safe.

Intracranial aneurysm (IA) is a socially important disease as a major cause of subarachnoid hemorrhage. Recent experimental studies mainly using animal models have revealed a crucial role of macrophage-mediated chronic inflammatory responses in its pathogenesis. However, as findings from comprehensive analysis of unruptured human IAs are limited, factors regulating progression and rupture of IAs in humans remain unclear. Using surgically dissected human unruptured IA lesions and control arterial walls, gene expression profiles were obtained by RNA sequence analysis. RNA sequencing analysis was done with read count about 60~100 million which yielded 6~10 billion bases per sample. 79 over-expressed and 329 under-expressed genes in IA lesions were identified. Through Gene Ontology analysis, 'chemokine activity', 'defense response' and 'extracellular region' were picked up as over-represented terms which included CCL3 and CCL4 in common. Among these genes, quantitative RT-PCR analysis using another set of samples reproduced the above result. Finally, increase of CCL3 protein compared with that in control arterial walls was clarified in IA lesions. Findings of the present study again highlight importance of macrophage recruitment via CCL3 in the pathogenesis of IA progression.

Introduction: Variability in usage and definition of data characteristics in previous cohort studies on unruptured intracranial aneurysms (UIA) complicated pooling and proper interpretation of these data. The aim of the National Institute of Health/National Institute of Neurological Disorders and Stroke UIA and Subarachnoid Hemorrhage (SAH) Common Data Elements (CDE) Project was to provide a common structure for data collection in future research on UIA and SAH., Methods: This paper describes the development and summarization of the recommendations of the working groups (WGs) on UIAs, which consisted of an international and multidisciplinary panel of cerebrovascular specialists on research and treatment of UIAs. Consensus recommendations were developed by review of previously published CDEs for other neurological diseases and the literature on UIAs. Recommendations for CDEs were classified by priority into 'Core,' 'Supplemental-Highly Recommended,' 'Supplemental,' and 'Exploratory.', Results: Ninety-one CDEs were compiled; 69 were newly created and 22 were existing CDEs. The CDEs were assigned to eight subcategories and were classified as Core (8), Supplemental-Highly Recommended (23), Supplemental (25), and Exploratory (35) elements. Additionally, the WG developed and agreed on a classification for aneurysm morphology., Conclusion: The proposed CDEs have been distilled from a broad pool of characteristics, measures, or outcomes. The usage of these CDEs will facilitate pooling of data from cohort studies or clinical trials on patients with UIAs.

Objectives: The goal for this project was to develop a comprehensive set of common data elements (CDEs), data definitions, case report forms and guidelines for use in unruptured intracranial aneurysm (UIA) and subarachnoid hemorrhage (SAH) clinical research, as part of a new joint effort between the National Institute of Neurological Disorders and Stroke (NINDS) and the National Library of Medicine of the US National Institutes of Health. These UIA and SAH CDEs will join several other neurological disease-specific CDEs that have already been developed and are available for use by research investigators., Methods: A Working Group (WG) divided into eight sub-groups and a Steering Committee comprised of international UIA and SAH experts reviewed existing NINDS CDEs and instruments, created new elements when needed and provided recommendations for UIA and SAH clinical research. The recommendations were compiled, internally reviewed by the entire UIA and SAH WG and posted online for 6 weeks for external public comments. The UIA and SAH WG and the NINDS CDE team reviewed the final version before posting the SAH Version 1.0 CDE recommendations., Results: The NINDS UIA and SAH CDEs and supporting documents are publicly available on the NINDS CDE ( https://www.commondataelements.ninds.nih.gov/#page=Default ) and NIH Repository ( https://cde.nlm.nih.gov/home ) websites. The recommendations are organized into domains including Participant Characteristics and Outcomes and Endpoints., Conclusion: Dissemination and widespread use of CDEs can facilitate UIA and SAH clinical research and clinical trial design, data sharing, and analyses of observational retrospective and prospective data. It is vital to maintain an international and multidisciplinary collaboration to ensure that these CDEs are implemented and updated when new information becomes available.

Background: The National Institute of Neurological Disorders and Stroke (NINDS) Common Data Elements (CDEs) have been generated to standardize and define terms used by the scientific community. The widespread use of these CDEs promotes harmonized data collection in clinical research. The aim of the NINDS Unruptured Intracranial Aneurysms (UIA) and Subarachnoid Hemorrhage (SAH), and Subject Characteristics working group (WG) was to identify, define, and classify CDEs describing the characteristics of patients diagnosed with an UIA and SAH. Thus, "Participant/Subject characteristics" is a set of factors defining a population of selected individuals and allowing comparisons with a reference population and overtime., Methods: Based on standard terms defined by the United States' Census Bureau, CDEs previously defined by several (Stroke, Epilepsy and Traumatic Brain Injury) NINDS CDE working groups literature and expert opinion of the WG, the "Participant/Subject characteristics" domain has been defined., Results: A set of 192 CDEs divided in 7 subsections: demographics (8 CDEs), social status (8 CDEs), behavioral status (22 CDEs), family and medical history (144 CDEs), pregnancy and perinatal history (8 CDEs), history data source reliability (3 CDEs), and prior functional status (3 CDEs) was defined. SAH is characterized by 6 core elements, all classified in the "Participant/Subject characteristics" domain. Four exploratory elements out of the 39 for SAH overall are in the "Participant/Subject characteristics" domain, and all remaining 182 CDEs in the "Participant/Subject characteristics" domain are classified as Supplemental-Highly Recommended elements., Conclusions: These CDEs would allow the development of best practice guidelines to standardize the assessment and reporting of observations concerning UIA and SAH.

Objective: We describe the technique for surgical "transaneurysmal" embolectomy in a patient with subarachnoid hemorrhage and multiple cerebral aneurysms who manifested large-vessel occlusion during coil embolization., Methods: An 84-year-old woman with subarachnoid hemorrhage and bilateral internal carotid artery (ICA)-posterior communicating artery and bilateral middle cerebral artery aneurysms (MCAs) was admitted to our institution. We performed clipping to the left ICA and MCAs; however, we could not find the rupture point of both aneurysms. We chose to treat 2 aneurysms on the other side by coil embolization. After complete coil embolization of a right ICA aneurysm, angiograms showed occlusion of the right MCA just proximal to an MCA aneurysm. Considering the risk of bleeding of an untreated MCA distal to the occlusion by endovascular thrombectomy, we performed open transaneurysmal embolectomy at the occlusion site and surgical clipping of the MCA. After cutting the aneurysmal wall, we inserted a suction tube into the cut surface of the aneurysm. The clot was gradually and completely pulled through the cut surface of the aneurysm. Finally, the aneurysm was completely clipped with titanium clips to preserve the M1 and M2 branches., Discussion: Different from usual surgical thrombectomy, suturing the vessel wall is not required for transaneurysmal embolectomy and the area of brain ischemia is confined. Aneurysms with the fragile wall may rupture during clearance of tissue on the aneurysmal surface, and suction may increase vessel damage., Conclusion: Transaneurysmal thrombectomy may be useful and safe for large-vessel occlusion just distal to cerebral aneurysms., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Multiple cerebral aneurysms are encountered in approximately 15% to 35% of patients harboring unruptured cerebral aneurysms. It would be of clinical value to determine which of them is most likely to rupture., Objective: To characterize features of the ruptured aneurysm relative to other concomitant fellow aneurysms in patients with multiple cerebral aneurysms., Methods: From a total of 5720 patients who were prospectively registered in the Unruptured Cerebral Aneurysm Study in Japan, a subgroup of patients with multiple cerebral aneurysms who developed subarachnoid hemorrhage was extracted for this post hoc analysis. Intrapatient comparisons of each aneurysm were carried out using aneurysm-specific factors such as size, location, and shape to identify predictors of rupture among the fellow aneurysms in a patient with multiple cerebral aneurysms., Results: Twenty-five patients with 62 aneurysms were identified from the total cohort of 5720 patients. With the distinctiveness in size, which means the aneurysm was the single largest among the multiple aneurysms, the ruptured aneurysm in each case was discriminated from the other coexisting aneurysms with a sensitivity of 0.76 and specificity of 0.86., Conclusion: Our results suggest that the largest aneurysm is likely to rupture among coexisting aneurysms in a patient with multiple cerebral aneurysms.

Background: Arachnoid cysts and intracranial aneurysms are not rare, but it is unusual for an aneurysm to be associated with an arachnoid cyst. The objective of this study was to reveal the association between arachnoid cysts and intracranial aneurysms., Methods: Methods included to report 3 cases with these 2 pathologies and to perform a systematic review of the English and Japanese literature using PubMed, Scopus, and Ichushi Web., Results: The first case was of a 46-year-old man with a subarachnoid hemorrhage on the basal cistern and bilateral arachnoid cysts in the middle fossa, the second was that of a 29-year-old woman with a subarachnoid hemorrhage at the basal cistern and an arachnoid cyst in the left middle fossa, and the third was that of a 60-year-old man with a right putaminal hemorrhage and contralateral unruptured aneurysm and arachnoid cyst. A literature search for similar cases found 27 patients., Conclusions: It was difficult to diagnose a ruptured aneurysm in some cases with an arachnoid cyst because computed tomography scan showed atypical findings, such as no hemorrhage, intracystic localized hemorrhage, or subdural hematoma. This review revealed that aneurysms and arachnoid cysts were significantly located ipsilaterally and that they occurred together in relatively young patients., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Giant thrombosed aneurysms of the vertebral artery (VA) are difficult to treat. Moreover, marked tortuosity of the parent VA complicates determination of the surgical approach. We report the case of a 71-year-old male patient who presented with gait disturbance. Magnetic resonance imaging revealed a giant thrombosed aneurysm of approximately 4cm in diameter located in the ventral region and to the right of the medulla oblongata. Computed tomography angiography showed that the right VA had extreme tortuosity, and that the VA union was in contact with the left 7th and 8th cranial nerves. Given that the aneurysm was thrombosed and causing a mass effect, we sought to trap it. In this case, because of the tortuous VA, intravascular team considered intravascular therapy to be too difficult. We made a question mark-shaped skin incision and used a wide bilateral suboccipital approach. The VA proximal to the aneurysm was occluded with an aneurysm clip using an approach from the right of the brainstem, while the VA distal to the aneurysm was occluded using a lateral suboccipital approach. When the VA and basilar artery are atherosclerotic and extremely tortuous, the distal and proximal aspects of the aneurysm can exist on both sides of the midline. In difficult cases such as that reported here, in which a giant VA aneurysm exceeded the midline of the anterior surface of the medulla, we believe that it is useful to employ a bilateral approach from both sides of the brainstem., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objective: The purpose of this study is to assess the validity and feasibility of macrophage imaging using an ultrasmall superparamagnetic iron oxide nanoparticle, ferumoxytol, in the cerebral aneurysmal wall in an animal model and in humans., Materials and Methods: Engulfment of ferumoxytol by primary culture of macrophages and RAW264.7 cells was assessed. Uptake of ferumoxytol was evaluated histologically in a cerebral aneurysmal model in rats. In an exploratory clinical study of magnetic resonance macrophage imaging, 17 unruptured aneurysms in 17 patients were imaged using thin-slice gapless magnetic resonance images of 2D-gradient-recalled echo (2D-GRE) and 3D-T1-fast-spin echo sequences on day 0 and of the same sequences with infusion of ferumoxytol 24 hours after the first imaging. Pre- and postinfusion images were evaluated independently by 2 medical doctors., Results: Engulfment of ferumoxytol was confirmed in vitro, but the amount of ferumoxytol uptake was independent of the activation state or the differentiation state. Ferumoxytol uptake in CD68-positive cells was observed in the cerebral arterial walls of 4 out of 15 (26.7%) experimentally induced aneurysms in rats. In a clinical study, 17 aneurysms were enrolled and 2 aneurysms were not assessed because of incomplete images. Eleven aneurysms without oral intake of recent anti-inflammatory agents of the remaining 15 aneurysms showed ferumoxytol uptake on 2D-GRE subtraction images, and the size of the aneurysms was significantly related to positive images., Conclusions: Ferumoxytol uptake was confirmed in cultured macrophages and in the cerebral aneurysmal wall in rats. Thin-slice gapless magnetic resonance imaging with ferumoxytol in human cerebral aneurysmal walls may reflect macrophages in the cerebral aneurysmal wall, but its application to small-sized lesions may be restricted., (Copyright © 2017. Published by Elsevier Inc.)

Background: A quantitative analysis comparing indocyanine green videoangiography (ICG-VAG) and fluorescein videoangiography (FL-VAG) in cerebrovascular surgery has not been reported so far., Objective: To clear the differences of characteristics of ICG-VAG and FL-VAG by quantitative assessment., Methods: We prospectively analyzed results from 23 patients (3 males; mean age at surgery: 60.9 years, range: 14-75 years) at our hospital from August 2014 to July 2015. Eighteen patients had cerebral aneurysms for clipping, and 5 had intracranial arterial stenosis for superficial temporal artery (STA)-middle cerebral artery bypass. We imported data from the operative image data, converted by Audio Video Interleave to Aquacosmos as picture fluorescence intensity-analyzing software. Regions of interest were set at the parent artery, dome of aneurysms, and perforating artery in cases of clipping of aneurysms, and setting at 3 points in STA, in case of bypass. The transition of fluorescence intensity at each region of interest was calculated and plotted using Aquacosmos., Results: Thick-walled artery, such as parent artery ( P = .0017) and STA ( P = .0182), was more significantly visualized by ICG-VAG than FL-VAG, whereas the perforating artery, especially in deep surgical fields, such as anterior communicating artery, internal carotid artery, and basilar artery, was better visualized by FL-VAG than ICG-VAG ( P < .0001)., Conclusion: In this quantitative analysis of fluorescence study, ICG-VAG showed greater efficacy than FL-VAG in visualizing relatively thick arteries, such as parent artery and STA. However, FL-VAG has greater efficacy than ICG-VAG in visualizing perforating artery, especially in deep surgical fields with characteristic vessel walls., (Copyright © 2017 by the Congress of Neurological Surgeons)

We experienced two cases in which aneurysm clips sprang from the applier. In case 1, a subdural haematoma from a ruptured anterior cerebral artery aneurysm was detected. When the clip was opened for final positioning, it suddenly sprang from the applier and ruptured the aneurysm. In case 2, the clip suddenly sprang from the applier as the surgeon opened the applier to clip an unruptured anterior cerebral aneurysm. These accidental phenomena are rare but dangerous. We present these cases to help prevent similar occurrences in the future. Video recordings of actual procedures can point to potential mechanisms and help reduce the incidence of this complication.

The intraoperative confirmation of blood flow direction is necessary in cerebral vascular surgery. Using indocyanine green video angiography (ICG-VAG) with the FLOW 800 system, we examined the transit time of the blood vessel of interest and semiquantitatively evaluated the delay time (T1/2max) from indocyanine green (ICG) injection into the donor artery in reconstructive surgery and the middle cerebral artery (MCA) in aneurysmal surgery. The direction of cerebral blood flow (CBF), which can often be confirmed by ICG-VAG, may be more difficult to determine with faster blood flow. Here, we report our findings regarding the feasibility of detecting CBF direction using the FLOW 800 system. Twenty patients undergoing superficial temporal artery (STA) to MCA anastomosis for carotid occlusive disease and 13 patients with a small MCA aneurysm clipping were evaluated using the T1/2max, semiquantitative method with the FLOW 800 system. In STA-MCA anastomosis cases, the regions of interest (ROIs) included: the proximal donor STA and a region more than 10 mm on the distal side of the donor STA near the anastomosis site. In MCA aneurysms, the ROIs included the proximal M1 and distal M2 sides of the MCA aneurysm. T1/2max was significantly shorter for the proximal sites compared to the distal sites for all subjects (ps < 0.01). T1/2max was shorter for all subjects in the proximal sites. The direction of CBF can be determined using the FLOW 800 system.

Background: Few reports have been published discussing surgical outcomes of paraclinoid aneurysms using multifarious treatments such as high-flow bypass., Material and Methods: We retrospectively analyzed findings from 127 consecutive patients (19 males, mean age at surgery: 56.8 years, range: 19-81 years) at our hospital. The size of aneurysms ranged from 2.7-43.2 mm (mean: 6.9 mm). Extradural anterior clinoidectomy was used to clip small aneurysms. As large or giant aneurysms required a longer temporal occlusion period and often could not undergo simple clipping, high-flow bypass with anterior clinoidectomy or cervical internal carotid ligation was performed to reduce aneurysm blood flow and induce thrombosis. We reviewed a postoperative modified Rankin Scale (mRS), radiographic outcomes, cerebral infarction, and visual disturbance. In addition, we analyzed factors relating to the outcomes and complications, with focus on the aneurysm size, location, and type of surgical treatment., Results: Good outcomes were achieved in all patients, as follows: mRS 0:100, mRS 1:16, mRS 2:11, and mRS 3-6:0. Among the 127 patients, complete exclusion of aneurysm was achieved in 119 cases (93.7%). Postoperative morbidity included ischemic lesions in 11 (8.6%) and visual disturbance in 24 (18.8%). Significant statistical differences were observed between ischemic complication and aneurysm size and location (P = 0.0001) and surgical treatment (P < 0.0001)., Conclusion: Surgical treatment of unruptured paraclinoid aneurysm has high efficacy with good outcomes and a high rate of complete exclusion. However, the rate of visual disturbance is relatively high. Careful surgical techniques and intraoperative monitoring are therefore required., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: We report a case of an internal carotid artery (ICA) aneurysm anomalously originating from the posterior communicating artery (PComA)., Case Description: Preoperative radiologic findings revealed a paraclinoid carotid artery aneurysm at the level of the distal dural ring. Because of the low rupture risk, there are no treatment indications for small paraclinoid or ICA-superior hypophyseal artery unruptured aneurysms. In this case, because of the patient's age and the irregular shape of the aneurysm, treatment was considered necessary. Intraoperative findings using microscopic and endoscopic angiography showed that the aneurysm originated from the proximal branched PComA. The PComA originated from the same level as the ophthalmic artery, and the superior hypophyseal artery originated from the distal side of the PComA., Conclusions: According to numerous reports, small incidental paraclinoid aneurysms have a lower risk of rupture and growth than PComA aneurysms. Preoperative radiologic examination of unruptured small aneurysms was performed using magnetic resonance angiography and three-dimensional computed tomography angiography. Because the ability of magnetic resonance angiography and three-dimensional computed tomography angiography to detect small branches of the ICA is inferior to digital subtraction angiography, the location of an unruptured ICA aneurysm should be evaluated with other diagnostic modalities besides magnetic resonance angiography and three-dimensional computed tomography angiography., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Objectives: The aim of this study was to identify risk factors for rupture of unruptured cerebral aneurysms (UCAs) in elderly Japanese patients aged 70 years or older., Methods: The participants included all patients 70 years of age or older in 3 prospective studies in Japan (the Unruptured Cerebral Aneurysm Study of Japan [UCAS Japan], UCAS II, and the prospective study at the Jikei University School of Medicine). A total of 1,896 patients aged 70 years or older with 2,227 UCAs were investigated. The median and mean follow-up periods were 990 and 802.7 days, respectively., Results: The mean aneurysm size was 6.2 ± 3.9 mm. Sixty-eight patients (3.6%) experienced subarachnoid hemorrhage during the follow-up period. Multivariable analysis per patient revealed that in patients aged 80 years or older (hazard ratio [HR], 2.02; 95% confidence interval [CI], 1.16-3.49, p = 0.012), aneurysms 7 mm or larger (HR, 3.08; 95% CI, 1.35-7.03, p = 0.007 for 7-9 mm; HR, 7.82; 95% CI, 3.60-16.98, p < 0.001 for 10-24 mm; and HR, 43.31; 95% CI, 12.55-149.42, p < 0.001 for ≥25 mm) and internal carotid-posterior communicating artery aneurysms (HR, 2.45; 95% CI, 1.23-4.88, p = 0.011) were independent predictors for UCA rupture in elderly patients., Conclusions: In our pooled analysis of prospective cohorts in Japan, patient age and aneurysm size and location were significant risk factors for UCA rupture in elderly patients., (© 2015 American Academy of Neurology.)

Objective: We endeavored to develop an unruptured intracranial aneurysm (UIA) treatment score (UIATS) model that includes and quantifies key factors involved in clinical decision-making in the management of UIAs and to assess agreement for this model among specialists in UIA management and research., Methods: An international multidisciplinary (neurosurgery, neuroradiology, neurology, clinical epidemiology) group of 69 specialists was convened to develop and validate the UIATS model using a Delphi consensus. For internal (39 panel members involved in identification of relevant features) and external validation (30 independent external reviewers), 30 selected UIA cases were used to analyze agreement with UIATS management recommendations based on a 5-point Likert scale (5 indicating strong agreement). Interrater agreement (IRA) was assessed with standardized coefficients of dispersion (vr*) (vr* = 0 indicating excellent agreement and vr* = 1 indicating poor agreement)., Results: The UIATS accounts for 29 key factors in UIA management. Agreement with UIATS (mean Likert scores) was 4.2 (95% confidence interval [CI] 4.1-4.3) per reviewer for both reviewer cohorts; agreement per case was 4.3 (95% CI 4.1-4.4) for panel members and 4.5 (95% CI 4.3-4.6) for external reviewers (p = 0.017). Mean Likert scores were 4.2 (95% CI 4.1-4.3) for interventional reviewers (n = 56) and 4.1 (95% CI 3.9-4.4) for noninterventional reviewers (n = 12) (p = 0.290). Overall IRA (vr*) for both cohorts was 0.026 (95% CI 0.019-0.033)., Conclusions: This novel UIA decision guidance study captures an excellent consensus among highly informed individuals on UIA management, irrespective of their underlying specialty. Clinicians can use the UIATS as a comprehensive mechanism for indicating how a large group of specialists might manage an individual patient with a UIA., (© 2015 American Academy of Neurology.)

Objective: To build a prediction model that estimates the 3-year rupture risk of unruptured saccular cerebral aneurysms., Methods: Survival analysis was done using each aneurysm as the unit for analysis. Derivation data were from the Unruptured Cerebral Aneurysm Study (UCAS) in Japan. It consists of patients with unruptured cerebral aneurysms enrolled between 2000 and 2004 at neurosurgical departments at tertiary care hospitals in Japan. The model was presented as a scoring system, and aneurysms were classified into 4 risk grades by predicted 3-year rupture risk: I, < 1%; II, 1 to 3%; III, 3 to 9%, and IV, >9%. The discrimination property and calibration plot of the model were evaluated with external validation data. They were a combination of 3 Japanese cohort studies: UCAS II, the Small Unruptured Intracranial Aneurysm Verification study, and the study at Jikei University School of Medicine., Results: The derivation data include 6,606 unruptured cerebral aneurysms in 5,651 patients. During the 11,482 aneurysm-year follow-up period, 107 ruptures were observed. The predictors chosen for the scoring system were patient age, sex, and hypertension, along with aneurysm size, location, and the presence of a daughter sac. The 3-year risk of rupture ranged from <1% to >15% depending on the individual characteristics of patients and aneurysms. External validation indicated good discrimination and calibration properties., Interpretation: A simple scoring system that only needs easily available patient and aneurysmal information was constructed. This can be used in clinical decision making regarding management of unruptured cerebral aneurysms., (© 2015 American Neurological Association.)

Background: Hunterian ligation is performed to reduce and to change the flow of an aneurysm; it is a surgical option for a complex aneurysm that cannot be managed by either clipping or coiling. However, it may be associated with adverse effects. This study was carried out to analyze how Hunterian ligation changed the flow dynamics of a particular cerebral aneurysm., Methods: A case of giant basilar tip aneurysm, in which Hunterian ligation resulted in rupture 6 months later, was subjected to computational fluid dynamic simulation. Among the simulations with various boundary conditions, the flow dynamic parameters of streamlines, velocities, and wall shear stresses were compared and analyzed qualitatively and quantitatively., Results: Hunterian ligation switched the parent artery from the basilar artery to the left posterior communicating artery. The changes in the direction and the diameter of the parent arteries resulted in the focal elevation of the shear magnitude and the high shear gradient on the posterior wall of the aneurysm after the ligation. These hemodynamic changes might have been associated with the eventual rupture of the aneurysm., Conclusions: Hunterian ligation is a useful flow diversion surgery, but it might worsen the flow dynamics in specific cases., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Objective: To present indications, surgical techniques, and outcomes of extracranial-intracranial (EC-IC) graft bypass., Methods: Between January 1996 and June 2011, 38 patients with large or giant internal carotid artery (ICA) aneurysms were treated using graft bypass, employing the radial artery (RA) or the saphenous vein (SV) as a graft. Preoperative balloon test occlusions were not performed in any of the cases. In 17 patients, the external carotid artery (ECA)-RA-M2 segment of the middle cerebral artery bypass was used for treatment, and ECA-SV-M2 bypass was used in 21 patients., Results: All aneurysms were completely trapped, and there were no subarachnoid hemorrhages or recanalizations of aneurysms during the follow-up period (8-170 months). Of the 38 bypasses, 36 (94.7%) remained patent, and there were no permanent neurologic deficits. Hyperperfusion syndrome was not experienced in this series. There were 2 temporary neurologic deficits. In 1 case using the RA, graft vasospasm occurred, and kinking occurred in 1 case using the SV. Another patient with a SV graft had to undergo an emergent revision of the graft 8 hours after the initial operation. One patient with a SV graft underwent a second operation to control an epidural abscess., Conclusions: Universal EC-IC graft bypass is a safe and effective method for treating large or giant ICA aneurysms., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Background and Purpose: To address the increasing need to counsel patients about treatment indications for unruptured intracranial aneurysms (UIA), we endeavored to develop a consensus on assessment of UIAs among a group of specialists from diverse fields involved in research and treatment of UIAs., Methods: After composition of the research group, a Delphi consensus was initiated to identify and rate all features, which may be relevant to assess UIAs and their treatment by using ranking scales and analysis of inter-rater agreement (IRA) for each factor. IRA was categorized as very high, high, moderate, or low., Results: Ultimately, 39 specialists from 4 specialties agreed (high or very high IRAs) on the following key factors for or against UIA treatment decisions: (1) patient age, life expectancy, and comorbid diseases; (2) previous subarachnoid hemorrhage from a different aneurysm, family history for UIA or subarachnoid hemorrhage, nicotine use; (3) UIA size, location, and lobulation; (4) UIA growth or de novo formation on serial imaging; (5) clinical symptoms (cranial nerve deficit, mass effect, and thromboembolic events from UIAs); and (6) risk factors for UIA treatment (patient age and life expectancy, UIA size, and estimated risk of treatment). However, IRAs for features rated with low relevance were also generally low, which underlined the existing controversy about the natural history of UIAs., Conclusions: Our results highlight that neurovascular specialists currently consider many features as important when evaluating UIAs but also highlight that the appreciation of natural history of UIAs remains uncertain, even within a group of highly informed individuals.

Background: The decision of whether to treat incidental intracranial saccular aneurysms is complicated by limitations in current knowledge of their natural history. We combined individual patient data from prospective cohort studies to determine predictors of aneurysm rupture and to construct a risk prediction chart to estimate 5-year aneurysm rupture risk by risk factor status., Methods: We did a systematic review and pooled analysis of individual patient data from 8382 participants in six prospective cohort studies with subarachnoid haemorrhage as outcome. We analysed cumulative rupture rates with Kaplan-Meier curves and assessed predictors with Cox proportional-hazard regression analysis., Findings: Rupture occurred in 230 patients during 29,166 person-years of follow-up. The mean observed 1-year risk of aneurysm rupture was 1·4% (95% CI 1·1-1·6) and the 5-year risk was 3·4% (2·9-4·0). Predictors were age, hypertension, history of subarachnoid haemorrhage, aneurysm size, aneurysm location, and geographical region. In study populations from North America and European countries other than Finland, the estimated 5-year absolute risk of aneurysm rupture ranged from 0·25% in individuals younger than 70 years without vascular risk factors with a small-sized (<7 mm) internal carotid artery aneurysm, to more than 15% in patients aged 70 years or older with hypertension, a history of subarachnoid haemorrhage, and a giant-sized (>20 mm) posterior circulation aneurysm. By comparison with populations from North America and European countries other than Finland, Finnish people had a 3·6-times increased risk of aneurysm rupture and Japanese people a 2·8-times increased risk., Interpretation: The PHASES score is an easily applicable aid for prediction of the risk of rupture of incidental intracranial aneurysms., Funding: Netherlands Organisation for Health Research and Development., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Background: Unruptured intracranial aneurysms are common, but their rupture can cause subarachnoid hemorrhage. When managing unruptured intracranial aneurysms, we must assess the natural course and management risks of individual aneurysms. In this paper, we summarize current knowledge based on the literature about the natural course of these aneurysms and management risks and present our management strategy., Methods: An extensive literature review was performed to find risk factors affecting the natural course and management outcomes of unruptured intracranial aneurysms., Results: Risk factors for rupture, strongly supported by the literature, were the size, specific location, and shape of the aneurysms. Management morbidity was significantly affected by aneurysm size and location and the patient' age., Conclusions: Unruptured intracranial aneurysms have various clinical characteristics, such as size, shape, and location and the patient's clinical condition, upon which management strategy should be stratified. In Japan, with national efforts to improve surgical and management standards, a national cohort study and individual case series have shown that the management morbidity of unruptured intracranial aneurysms is low. To improve care and to perform safer interventions, we must continue to seek better and less-invasive management methods and techniques.

The surgical procedure used to treat an unruptured intracranial aneurysm (UIA) has controversial effects on cognitive function. From January 2010 through December 2012, we enrolled patients who underwent surgical clipping for a UIA. Patients were tested within one week prior to surgery and again postoperatively (6.8 ± 2.3 days) using a neuropsychological battery comprising the Mini-Mental State Examination, the Trail Making Test (TMT), the Frontal Assessment Battery (FAB), and Raven's colored progressive matrices (RCPM). Differences between preoperative and postoperative test scores for each examination were analyzed across individuals. In an additional subgroup analysis, patients were grouped according to age (< 65 or ≥ 65 years), the largest dimension of the aneurysm, the location of the aneurysm (i.e., anterior communicating artery, internal carotid artery, or middle cerebral artery) and operation duration. Paired student's t-tests were used to examine potential differences between groups. Two-tailed P-values < 0.05 were considered significant. Seventy-one patients were included in the analysis. The surgical procedure used to correct a UIA resulted in significant changes in neuropsychological scores. After the procedure, the TMT-A score declined significantly, whereas the FAB and RCPM scores were significantly improved. In the subgroup analysis, a significant deterioration in TMT-A score was observed in older patients and those with larger aneurysms, anterior communicating artery aneurysms and longer surgeries. Our findings, therefore, indicate that the surgical procedure to correct a UIA affects cognitive function. Older patients and those with large aneurysms, anterior communicating aneurysms, and long operations represent the high-risk groups.

A 60-year-old woman was admitted to the hospital due to a sudden loss of consciousness. Computed tomography (CT) revealed a thick subarachnoid hemorrhage in almost all of the parachiasmatic cisterns, including the sylvian cisterns, with mild hydrocephalus. Three dimensional (3D)-CT angiography showed an irregularly shaped aneurysm at the bifurcation of the left A2 and the frontopolar artery. The aneurysm was successfully obliterated by clipping through the interhemispheric approach. CT performed immediately after the operation showed a newly formed left temporal subpial hematoma. The patient's neurological status improved gradually after surgery, but deteriorated again 2 days after the operation. CT revealed an enlarging right sylviansubpial hematoma. The subpial hematoma was rapidly removed surgically. Slight hemiparesis and impaired higher cognitive function remained after a shunt procedure for subsequent hydrocephalus. Emerging sylvian hematoma associated with a distant site of a ruptured aneurysm is extremely rare. However, adequate attention is required in cases with a thick subarachnoid hemorrhage in distant fissures.

Background: The natural history of unruptured cerebral aneurysms has not been clearly defined., Methods: From January 2001 through April 2004, we enrolled patients with newly identified, unruptured cerebral aneurysms in Japan. Information on the rupture of aneurysms, deaths, and the results of periodic follow-up examinations were recorded. We included 5720 patients 20 years of age or older (mean age, 62.5 years; 68% women) who had saccular aneurysms that were 3 mm or more in the largest dimension and who initially presented with no more than a slight disability., Results: Of the 6697 aneurysms studied, 91% were discovered incidentally. Most aneurysms were in the middle cerebral arteries (36%) and the internal carotid arteries (34%). The mean (±SD) size of the aneurysms was 5.7±3.6 mm. During a follow-up period that included 11,660 aneurysm-years, ruptures were documented in 111 patients, with an annual rate of rupture of 0.95% (95% confidence interval [CI], 0.79 to 1.15). The risk of rupture increased with increasing size of the aneurysm. With aneurysms that were 3 to 4 mm in size as the reference, the hazard ratios for size categories were as follows: 5 to 6 mm, 1.13 (95% CI, 0.58 to 2.22); 7 to 9 mm, 3.35 (95% CI, 1.87 to 6.00); 10 to 24 mm, 9.09 (95% CI, 5.25 to 15.74); and 25 mm or larger, 76.26 (95% CI, 32.76 to 177.54). As compared with aneurysms in the middle cerebral arteries, those in the posterior and anterior communicating arteries were more likely to rupture (hazard ratio, 1.90 [95% CI, 1.12 to 3.21] and 2.02 [95% CI, 1.13 to 3.58], respectively). Aneurysms with a daughter sac (an irregular protrusion of the wall of the aneurysm) were also more likely to rupture (hazard ratio, 1.63; 95% CI, 1.08 to 2.48)., Conclusions: This study showed that the natural course of unruptured cerebral aneurysms varies according to the size, location, and shape of the aneurysm. (Funded by the Ministry of Health, Labor, and Welfare in Japan and others; UCAS Japan UMIN-CTR number, C000000418.).